Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The effects of climate changeon lake Balaton

Varga Györgyvarga.gyorgy@ovf.hu

General Directorate of Water Management, Budapest

VITUKI Hungary Kft. Országos Meteorológiai Szolgálat

Local Climate Adaptation CapacityBuilding Event

Lake Balaton

Content of the presentation

- Data and information about the water balance and about thewater level changing of Lake Balaton;

- The scope of the data resulting from the ALADIN-Climate model for the estimation of the future hydrological cycle; opportunities and constraints;

- The estimation of the natural changes in the water resources(the correct amount of precipitation, evaporation and inflow)for different climatic periods. (methods, results, conclusions);

- summary and outlook;

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

BUDAPEST

SiófokKeszthely

Lake Balatonand its catchment area

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The water level of Lake Balaton from 800 BC to present day

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

Annual minimum, average and maximum water level

of Lake Balaton1863-2015

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The geometric characteristics of Lake Balaton

(in case of 104.17 m water level above Baltic sea level)

the catchment area: 5775.0 km2

open water area: 571.7 km2

the area of reeds: 16.8 km2

all lake surface: 588.5 km2

length: 76.5 kmthe average width: 7.5 kmaverage depth: 3.36 mvolume: 1.978 km3

Small-Balaton Water Protection System: ~ 72 km2

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The elements of the water balance

and the water balance equation

W = (P + I) – (E + O + Wc)

WN = (P + I) – E

P – precipitation on the lake surface

I – inflow to the lake

E – evaporation from lake surface

O – outflow from the lake

Wc – water consumption

W – change in water storage

WN - natural change in the water resources of the lake

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

Average and extreme values of water balance of Lake Balaton

according to data between 1921 and 2015

Elements of water balance

minimum (mm/annum)

average(mm/annum)

maximum (mm/annum)

Precipitation 309 617 929

Inflow 236 856 1974

Evaporation 723 897 1073

Natural change of water resources

-281 576 2031

Outflow 0 557 1791

Water consumption

15 28 51

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

Local Climate Adaptation Capacity Building Event; Országos Meteorológiai Szolgálat, 2016. február 19.

The annual natural changesin water resources of Lake

Balaton (1921-2015)

The meteorological data used for theestimation of the natural changes in

the water resources for different climatic periods in the future

Weighted regional averages for the catchment area of the lake

Monthly precipitation (mm) (CC 1961-1990; 1961-1990 ALADIN; ALADIN 2021-2050, 2071-2100 ALADIN)Monthly average temperature (°C) (CC 1961-1990; 1961-1990 ALADIN; ALADIN 2021-2050, 2071-2100 ALADIN)

Weighted averages for the lake area

Monthly precipitation (mm) (CC 1961-1990; 1961-1990 ALADIN; ALADIN 2021-2050, 2071-2100 ALADIN)Monthly average temperature (° C) (CC 1961-1990; ALADIN 1961-1990; 2021-2050 ALADIN; 2071-2100 ALADIN)monthly mean wind speed (measuring height: 10 m (m / s)) (CC 1961-1990; 1961-1990 ALADIN; ALADIN 2021-2050, 2071-2100 ALADIN)monthly relative humidity (%) (1961-1990 CC; ALADIN 1961-1990; 2021-2050 ALADIN; 2071-2100 ALADIN)

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

Thoughts about the interpretation, uses and limitations of the

meteorological data (ALADIN-Climate model simulations results)

The classical sense "long-term predictability importance" of the climate models can not be achieved. Climate time scale to be considered the results of climate models as a statistical population where there is no prognostic significance of a given forecast which specific date applies, and the models reliability classified according to the statistical characteristics of a selected period of which accurately able to reflect.Forward-looking model results are not in themselves but in relation to their own models to interpret the reference period, and the systematic error model for the future and the past are partially eliminated by the difference each other; add or change the values of the reference period values calculated from the measurements (with the relative change in the measurement and multiply the value change).Within the thirty-year periods, the annual information form of a statistical population, which are interchangeable in time. This means that any annual series of any year of the corresponding period.

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The estimated change inprecipitation falling in the

catchment area of Lake Balaton (%)

ALADIN 2150 (adj.) = (CC 6190 average) * k, where k = (ALADIN 2150)/(ALADIN 6190 avg)ALADIN 7100 (adj.) = (CC 6190 average) * k, where k = (ALADIN 7100) /(ALADIN 6190 avg)

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The estimated change inprecipitation falling in the surface

of Lake Balaton (%)

ALADIN 2150 (adj.) = (CC 6190 average) * k, where k = (ALADIN 2150)/(ALADIN 6190 avg)ALADIN 7100 (adj.) = (CC 6190 average) * k, where k = (ALADIN 7100) /(ALADIN 6190 avg)

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The estimated change of theannual mean temperature of the

catchment area

ALADIN 2150 (adj.) = (CC 6190 average) + k, where k = (ALADIN 2150 -ALADIN 6190 avg)ALADIN 7100 (adj.) = (CC 6190 average) +k, where k = (ALADIN 7100 - ALADIN 6190 avg)

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The estimated change in annual regional (actual) evaporation (mm)

of the catchment area of Lake Balaton

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The periodic average of the annual runoff (in the water balance of the lake: the

inflow) from the catchment area in caseof different climatic periods (mm/year)

Within 30 years the number of windows climate negative annual precipitation-evaporation difference can be characterized in the

following years:

1 year in the period 1961-19906 years in the period 2021-205013 years in the period 2071-2100

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The estimated change of the air temperature measured

above the water surface of thelake (°C)

ALADIN 2150 (adj.) = (CC 6190 average) + k, where k = (ALADIN 2150 -ALADIN 6190 avg)ALADIN 7100 (adj.) = (CC 6190 average) +k, where k = (ALADIN 7100 - ALADIN 6190 avg)

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

Local Climate Adaptation Capacity Building Event; Országos Meteorológiai Szolgálat, 2016. február 19.

The estimated change of therelative humidity measured above the water surface of the lake (%)

ALADIN 2150 (adj.) = (CC 6190 average) + k, where k = (ALADIN 2150 -ALADIN 6190 avg)ALADIN 7100 (adj.) = (CC 6190 average) +k, where k = (ALADIN 7100 - ALADIN 6190 avg)

The estimated change of thewind speed measured above the

water surface of the lake (%)

ALADIN 2150 (adj.) = (CC 6190 average) * k, where k = (ALADIN 2150)/(ALADIN 6190 avg)ALADIN 7100 (adj.) = (CC 6190 average) * k, where k = (ALADIN 7100) /(ALADIN 6190 avg)

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The estimated change of thelake evaporation

(%)

EW = a*(E-e)*(0,59+0,013*v)*n

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The estimated change of theannual changes in the natural

water resources(mm/year)

The number of negative annual change of natural water resources is characterized by years:

7 years in the period 1961-19909 years in the period 2021-205019 years in the period 2071-2100

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

The studies carried out further development directions

Single - in this case the ALADIN-Climate - model simulationresults of the investigation can not be made unfoundedstatements about the uncertainty of the results.

The uncertainties can be described correctly only byusing multi-model experiment. Two models already use agood starting point for a basic uncertainty quantification of.Therefore, the interpretation of future changes definitelyneed at least one suitably selected model test results ofthe investigation.

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

Summary and Outlook

Overall, the lake water balance of the decrease and the increase ofspending on the revenue side is likely. This double effect compared to theaverage conditions of the reference period - particularly in the second windowperiod of future climate (2071-2100) - will fundamentally change thehydrological picture of the lake. The lake water exchange activity hasdeteriorated significantly, and often occur in permanent outlet periods, andeven the last decades of the 21st century, the lake was lifted virtuallyno outlet to change.

The water flows are influenced by natural factors, the evolution of the estimateduncertainty of the strength of anthropogenic effects:- Existing and directly affecting the catchment area of the lake water uses(abstractions, discharges the water system)- Land use in the catchment, its evolution both natural and anthropogenicinfluences (forestation, cultivation methods and changes in theregulation of runoff, changes in the extent of free water surfaces,etc.).

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred

Thank you for your attention!

Thanks to

Dr. Béla Nováky

Gabriella Szépszó

Anett Csorvási

Emese Homolya

for their help in the preparation of the study and the presentation.

Local Climate Adaptation Capacity Building Event; September 22, 2016; Balatonfüred